#!/usr/bin/env bash

# Either set DIR to the same value as supybot.plugins.PackageInfo.aptdir,
# or use the --dir command-line option.
DIR=""

# Be quiet by default.
VERBOSE=0


## Please don't change anything below this line, unless you really know what
## you are doing and don't bother me with whatever errors it produces :)

# Print usage information.
usage() {
    echo "Usage $0 [OPTION]..."
    echo "Updates the APT package cache for PackageInfo"
    echo ""
    echo "-h, --help            Display this message and exit."
    echo "-v, --verbose         Be more verbose than normal."
    echo "-V, --very-verbose    Be even more verbose than normal."
    echo "-d, --dir[=DIR]       Sets the directory to use when updating the APT package cache."
    echo ""
    echo "Note:"
    echo "  Please separate each option with a space, eg:"
    echo "      $0 -v -d /home/bot/aptdir"
    echo "  Rather than:"
    echo "      $0 -vd /home/bot/aptdir"
    echo ""
    echo "This script is intended to be ran automatically (eg: cron), so it shows no output by default."
    echo "You can make the script more verbose with either the -v/--verbose or -V/--very-verbose options."
    echo "The -d/--dir option sets the directory where this script looks for *.list files for apt-get."
}

# Prints an error message, usage (above), then exit with the specified exit value.
error() {
    local exit_val=$1
    shift
    echo $@ >&2
    usage >&2
    exit $exit_val
}

# Runs apt-get update in the specified directory for the specified distribution.
update_apt() {
    local apt_dir="$1"
    local dist="$2"
    local apt_args=""

    if [ $VERBOSE -eq 0 ]; then
        apt_args="-qq"
    elif [ $VERBOSE -eq 1 ]; then
        apt_args="-q"
    fi

    apt-get $apt_args -o="APT::Architecture=i386" \
        -o="APT::Architectures::=i386" \
        -o "APT::Architectures::=amd64" \
        -o="Dir::State::Lists=$apt_dir/$dist" \
        -o="Dir::State::Status=$apt_dir/$dist.status" \
        -o="Dir::Cache=$apt_dir/cache" \
        -o="Dir::Etc::SourceList=$apt_dir/$dist.list" \
        update

    return $?
}

# main()

# Acepted arguments are:
# -h,--help
# -v,--verbose
# -V,--very-verbose
# -d,--dir[=DIR]

# Check command-line arguments
while [ $# -gt 0 ]; do
    case "$1" in
        -h|--help)
            usage
            exit 0
            ;;
        -v|--verbose)
            VERBOSE=1
            ;;
        -V|--very-verbose)
            VERBOSE=2
            ;;
        -d|--dir)
            [ -z "$2" ] && error 1 "\"-d|--dir\" requires an argument."
            shift
            DIR="$1"
            ;;
        --dir=*)
            DIR="${1:6}"
            [ -z "$DIR" ] && error 1 "\"--dir\" requires an argument."
            ;;
        -*)
            error 1 "Unknown option \"$1\"."
            ;;
        *)
            error 1 "This script takes no non-argument parameters."
            ;;
    esac
    shift
done

apt_get=$(which apt-get 2>/dev/null)

# Check that apt-get exists and bail if it doesn't.
if [ $? -ne 0 ]; then
    echo "ERROR: apt-get not found. Please install apt-get in your \$PATH." >&2
    exit 1
fi

#TODO: Remove this section and error out if DIR is not set,
#      This could hide errors where DIR/-d was not set, an error message.
if [ -z "$DIR" ]; then
    DIR=/home/bot/aptdir
    echo "WARNING: No DIR set and no -d/--dir option given, defaulting to \"$DIR\"" >&2
    echo "WARNING: Please set DIR on line 5 of $(readlink -f $0) or use the -d/--dir option" >&2
fi

#[ -z "$DIR" ] && error 1 "ERROT: Please set DIR on line 5 of $(readlink -f $0) or use the -d/--dir option"

DIR="$(echo $DIR | sed 's,/*$,,')" # Normalize $DIR

items=$(ls "${DIR}"/*.list 2>/dev/null)
[ $? -ne 0 ] && error 1 "Could not find \"*.list\" files in \"$DIR\"."

for DIST in $items; do
    [ -h "$DIST" ] && continue # Ignore symbolic links
    # Extract the distribution name from the .list file name.
    DIST="${DIST:${#DIR}}"
    DIST="${DIST/.list}"
    DIST="${DIST:1}"

    touch "${DIR}/${DIST}.status" # Create APT status file
    mkdir -p "${DIR}/${DIST}/partial" # APT needs this to exist
    update_apt "$DIR" "$DIST" # Update the package list with apt-get
done